Date: April 4, 2007
From: Allan Dodds <dodds@ucr.edu>
Source: China Daily [edited]
<http://www.chinadaily.com.cn/china/2007-04/04/content_842930.htm>

Warm winter weather, combined with the prolonged drought that has gripped a wide swathe of China, has put crops at risk across the country, officials have said.

Unseasonably high temperatures last winter [2006-2007] caused wheat, the country's 2nd most important crop after rice, to grow extraordinarily fast in many areas, making it more vulnerable to drastic weather changes, the Ministry of Agriculture said yesterday [3 Apr 2007].

The average temperature during the past winter was minus 2.4 deg C (28 deg F), nearly 2 deg C higher than normal, official statistics showed. The higher temperature has caused 3.1 million hectares of wheat, or 15 percent of the total area planted with winter wheat, to grow abnormally lushly, ministry official Wang Xiaobing said.

In addition, the warm weather allowed insects and bacteria to survive the winter, meaning farms could expect to see more pests and diseases this year [2007], he said. For example, at least 840 000 hectares (2.1 million acres) of wheat, mostly in Central China, are suffering from yellow rust disease, a kind of fungus that affects plants, according to ministry statistics.

"We must bring the infection under control or it could spread to other key grain producers, like Hebei Province in North China, Henan Province in Central China, and Shandong in East China," Wang told China Daily.

Wang said the ministry has urged local agricultural departments to prepare contingency plans for possible cold snaps and strong winds that may affect wheat seedlings.

Meanwhile, the drought that has stretched through the winter has adversely affected an even larger area.

At least 13.5 million hectares (33.4 million acres) of farmland in China had been hit by drought by the end of last month [March 2007], according to the latest statistics from the State Flood Control and Drought Relief Headquarters.

Ministry of Agriculture official Wang said he believed the current drought would not make a significant dent in the country's grain production.

Wheat accounts for nearly 90 percent of the crops harvested in summer. Summer grain, mainly wheat and early rice, which is sown in spring, contributes to a quarter of China's total grain production, according to Wang.

[Byline: Zhao Huanxin]

--

J. Allan Dodds

Former ProMED-mail plant disease moderator Professor of Plant Pathology College of Natural and Agricultural Sciences University of California Riverside, CA 92521 USA <dodds@ucr.edu>

[Wheat stripe rust, also called yellow rust disease, is caused by the fungus _Puccinia striiformis_. It is distributed generally throughout wheat production areas at high elevations and in the northern and southern areas of temperate regions. Symptoms on wheat are yellow stripes on leaves and stunting of plants. Yield losses of 40 percent can be common with some fields totally destroyed. Severe losses result when spikes are infected. Infection occurs in cool moist conditions, spores dispersed by wind. It is primarily a disease of wheat (_Triticum_ sp.) and a few barley (_Hordeum vulgare_) cultivars worldwide. Control by fungicides, cultivation management and use of resistant cultivars.

Information on wheat stripe rust -- including photographs of symptoms is available at
<http://www.oznet.k-state.edu/path-ext/factSheets/Wheat/Wheat%20Stripe%20Rust.asp>,
and <http://www.ars.usda.gov/Main/docs.htm?docid=9918>
- Mod.DHA]

[see also in the archive:

2006
Cereal Rust Update - USA (10) 20060811.2258